This relates generally to image sensors and, more particularly, to image sensors having color filters.
Image sensors are commonly used in electronic devices such as cellular telephones, cameras, and computers to capture images. In a typical arrangement, an electronic device is provided with an array of image pixels arranged in pixel rows and pixel columns. Each image pixel in the array includes a photodiode that is coupled to a floating diffusion region via a transfer gate. Each pixel receives incident photons (light) and converts the photons into electrical signals. Column circuitry is coupled to each pixel column for reading out pixel signals from the image pixels. Image sensors are sometimes designed to provide images to electronic devices using a Joint Photographic Experts Group (JPEG) format.
Conventional image sensors sometimes include a color filter element above each pixel. In one typical arrangement, color filter elements may be arranged in a Bayer mosaic pattern. The Bayer mosaic pattern consists of a repeating unit cell of two-by-two image pixels, with two green image pixels diagonally opposite one another and adjacent to a red image pixel diagonally opposite to a blue image pixel. Conventional image sensors have a color filter pattern such as the Bayer mosaic pattern that repeats across the array without variation in pattern or wavelength absorption. This may limit image sensor performance when a variable response is desired.
It would therefore be desirable to provide improved color filter arrays for image sensors.